Drill



@et 2359 W23.

A. E slMPsoN 2 Sheets-Sheet 1 www (Oct. 23, E923. 11,473,866

A. E. SIMPSON DRILL Filed April 6, 1921 2 Sheets-Sheet 2 Patented @et 23, 1223.

ALEERT E. SIMPSON,

heiligen DE BURY, ENGLAND.

DRILL.

Application led April 5,

To aZZ 'whom t may concern.

Be it known that 1, nnnnr E. SiMrsoN, a subject of the King of Great Britain, and a resident of Bury, England, have invented certain new and useful improvements in Drills, of which the following is a specication.

his invention relates to a tool which is designed to countersink the bottom edge of a hole made by the tool. The tool takes the fornrof a drill so constructed that both edges of the hole intde by it may be countersunk simultaneously or the bottom edge may be countersunk independently of the top edge.

rlfhe novel features of the invention will appear from the detailed description thereof taken in connection with the accompanying drawings forming part of this specification.

Referring to the drawings:

Fig.v 1 is an elevation showing the blank from which is inadea tool or drill embodying my invention.

Fig. 2 is an elevation showingthe blank in another stage of.V manufacture.

Fig. 3 is an elevation showing a drill made from the blank shown in Figs. 1 and 2.

Fig. 4 is an end view of the drill shown in Fig. 3.

Figs, 5, 6 and 7 are views showing three stages in drilling and countersinking both sides of plate by the same tool.

lFig. 8 is an elevation showing a blank from which is'made another forrn of drill embodying iny invention.

`ldig. 9 is an elevation showing a drill made from the blank shown in Fig. 8.'

Figs. 10. 11 and 12 are views showing three stages in drilling and countersinking both sides of a plate by the drill shown in Fig. 9, Fig 12additionally showing in seotion a forni of chuck that may be used for holding the drill.

1n the drawings like characters of reference indicate like parte throughout the several views.

The tool consists of a drill 10: a body portion 11'. of less radius than the drill, arranged eccentrically thereto whereby a step 12 is formed.A this step forming a cutting edge. and eccentric or body portion 13 of greater radius than said reduced portion arranged eccentrically with Vrespect to said reduced portion. The arrangement is suoli that after the drill has passed through the 1921. Seria11l'o.458,949.

plate or other object being drilled, the cutting edge 12 is forced laterally against the lower edge 'of the hole by the eccentric 13 which, as the drill is pushed through the hole, tends to lind a seat in the hole.

ln the form of the invention shown in Fig. 3 the eccentric 13 is of the same diameter as the drill 10 and it will therefore enter the hole made by the drill. The shoulder between the two portions 11 and 13 is beveled. As the shoulder is forced into the hole the cutting edge 12 is forced against the bottom edge of the hole thus countersinking the same. The cutting action continues until the eccentric 13 has fully entered the hole when further downward movement of the tool will be without effect since such movement merely moves the cutting edge 12 away from the edge of the hole. However, it is often desirable to countersink the upper edge of the hole and means are therefore provided for that purpose. The eccentric or body portion 13 is surrnounted by an enlarged body 14. The shoulder or ste-n adjacent the body portion 13 is beveled and milled to provide one or more cutting edges l15 which, when the part 13 is entered into the hole.y serve to countersink the plate as will be readily understood. ln other words the tool functions like any ordinary countersink drill from the body portion 13 upwardly except. of course. that the tool has a wabblv motion due to the eccentricity of the drill with respect to the body portion 13.

The axial distance between the cutting edge 12 and the beveled shoulder of the eccentric 13 will be of the same thickness as the plate or other obiect being drilled. The amount of throw or eccentrieitv between the reduced body nortion'll and the drill at one end and the portion 13 at the other end will vvary according to the diameter of the countersinlr desired at the underside of the plat-e.

ln the form of the invention shown in Fig. 9. the vertical distance between the root of the cutting edge 15 and the root of thebevel of the eccentric part 13", which corresponds to the part 13 of the tool shown in Fig. 3, is quite small as compa-red with that in the other forni of the invention. The Inode of operation of the tools, however, is substantially the same. The" beveled shoulder 13 meets the edge of the hole ahead of the cutting edge 15 and forces the cutting edge 12 into engagement with the bottom edge oi" the hole. edge l5 subsequently comes into contact with the upper edge oft the hole and counter sinking ot bothedges will then take place at the same time. Countersinking ot both ends of the hole will cease in` both forms ot the invention when that part ot the reduced body portion ll between adjacent cutting edges l2 and l5 is brought into contact with the wall of the hole.

The method of forming` the tool will be readily understood from Figs. l, 2 and 8. A bar is turned to provide a suitable shank S whereby the toolY may be suitably held. The part a7 is concentric to thev shank and forms the drill 10. The part by is cut away onone side and the part c, is cut from the part a. The beveled end of the part d after being milled for ther edge l5 is backed ott to provide clearance for the cutting edgeA In the drill shown in Fig. 9 the edge l5 is backed oit so as to be a short distance above the'diame'trically opposite bevel as will be readilyunderstood. Only one. cutting edge 15 is formed sincethe point diametrically opposite said edge is the heel which rubs on Ythe upper edge of the hole during the countersinking operation. v

Any suitable means may be provided for holding the. tool so as to permit the necesL j saryv wabbling during the countersinking operation. ln ,Fig. 12 1 have shown a simple form oi chuck for this purpose which consists o-t'two socket members 20 and 2l which are loosely connected, a springpressed key 22 in the member 2O entering a key way in the stein ofthe member 21 to prevent relative rotation. The shank of the.- drill is suitably secured to the socket member 2lV as by a set screw.

So tar asl am aware it has not been nossible prior to my invention to countersink the bottom edge ot' a'hole by means ot the tool that made the hole. It is therefore to be understood that while I havey described the 'invention with considerable particularity/the invention is not limited to the forms shown. I intend only such limitations as may beimposed by the appended claims. l

What lvclaim is :A

l. In combination. a drill having a body of" viven size. a drill stem extending eccentrically trom one end of said body whereby a step is tormed, a member extending eccentrically with respect to the drill from the other end ot Vsaid body whereby a step opposite tothe vfirst named step is formed, saidlirst named step being a cutting edge, anda cutting edge disposed rearwardly `'from said cutting edge.

2. A. tool comprising al drill ot the straight ute type, an inwardly directedV ste above i the cutting pointV of the drill,-the s loulder The cutting 4radius greater than the `radius of said re duced ortion said bod i Dortion bein T eccentri cally arranged with respect to the drill and said reduced portion.

4.-. .a tool comprising a drilly a reduced body portion on said drill above the cutting` point thereof arranged eccentrically with respect to the drill 'whereby a step 'is'formetb said step forming a cutting` edge, another body portion above said reduced bodypor-` tion ot a radius greater than the radius of said reduced portion, said body portion being eccentrically arranged with respect to the drill and said reduced portion, andra cutting' Vedge disposed rearwardly of vthe body'portion and overstanding` and spaced trom said step. i j

A. tool comprising a drill,V a body portion of less radius than that of the drill arrangedV eccentrically with respect toV theV Va cutting edge, a cutting edge extending from the reduced body portion at a point above said step` and a projecting body'portion between said cutting edges but on the opposite side ot the drill', said body portion being oi a radius greater'than the radiusV of said restricted portion and eccentrically arranged with respect thereto.VV

6. Means :tor countersinking the under side ot al plate comprising a tool having a drill, an inwardly directed cutting edge above the Vcutting point of the drill, a projection at one side of the tool opposite said cutting edge, saidvr projection being eccentrically arranged with respect to the drill whereby as said projection is entered into the hole made by the drill, the latter is caused to run eccentrically' with respect n thereto and said edge brought into cutting engagement hole.` j Y.

7. A tool' comprising;- a drill, an inclined cutting edge flaring upwardly vand outwardly with respect to the drill, a second cutting edae flaring ydownwardly and outwardly with respect'to the drill, al recessed portion on the drill between said cutting edges, and

with the bottom edge of the means projecting laterally of the drillY opposite and `between* said cutting edges, saidV S il lill' icc means being adapted to cause lthe drill to run eccentrica-Hy with respect to the hole made by the drill.

8. A tool lcomprising a drilha recessed ortion at one side of the drill whereby a formed, said step being inclined downwardly and outwardly and forming a cuttingY edge longitudinally spaced from the point of the drill7 a part flaring outwardly and upwardly from the drill at a point above step on the opposite side of the drill, said means servingto cause the drill to run eccentrically with respect to the hole rnade by the drill.

9. iiitool comprising a drill, a reduced bodj,7 portion. on the drill longitudinally spaced from the point of the same, said portion being` eccentric with respect to the drill whereby a step is formed at one side thereof, said sten being' a. cutting edge, and a part projecting laterally from the drill diametricaliy opposite and above said step, said part serving to canse the drill. to run eccentricallj7 with respect to the hole made by the drill.

l0. A, tool for making a hole and countersinking both edges of the saine comprising a drill, spaced opposed cutting edges remote from the cutting point of the drill, the roots of said cutting edges beginning at points inwar/elly of the cutting surface of the drill, and an inclined part opposite said edges for engaging); the top edge of the hole made by the drill, to impart a transverse movement of the drill.

l1. ,fi combined drill and forward counter-sink comprising a drill having an eccentric enlarged rear body portion and a step forward thereof having a rearwardly directed cutting edge.

' A combined drill and forward countei. sink comprising a drill having a forwardly tapered eccentric enlarged rear body portion and a step forward thereof having nrwardly directed. cutting edge. A c inbined drill and forward counter-sinh comprisingT a drill having a forwardly tapered eccentric enlarged rear body portion and a step forward thereof having a rearwardly directed cutting edge, there being` also a further rearward enlargement concentric :th that r'lrst mentioned and having a forward cutting edge.

ln witness whereof, l have hereunto set iny hand this 18th day of March 1921.

ALBERT E. SlMPSON. 

